Answer: but your question doesnt make sense
Explanation:
The correct answer should be additionally.
The word additionally would provide the best transition between these two sentence. It is so because you have one idea in the first sentence, and then you want to show another idea very similar to the first one in the second sentence. Using additionally to convey that is the way to go.
Usually what element helps you identify the theme of a story is what lesson the main character learns, or any important idea or refrain throughout the story.
In the story the odyssey if that's what you are talking about then the sign was the two eagles dropping down on the congregation(group of people) fighting with their sharp talons ripping each other apart and its impending doom for them.
(delete the comment below your question i put it there because i thought i wasn't going to be able to comment the answer because 2 people were answering)